Help! Term paper gone on computer! Need to restore it to its ''previous'' state!

Well, I was using Adobe Digital Editions, Reading a book, and Writing bookmarks&notices (LOTS OF THEM) about important stuff, for more than about 100 pages.

But suddenly, the program crahed while I was Writing stuff on it, and now all my texts and highlights are gone!

I need this for my exam (University exam - international relations).

This is sorta the final exam right now, and not only my economy, but also my future education possibilities etc are dependent on it.

I CAN NOT RE-START my work from scratch, as it would take too much time, the paper has to be turned-in soon.

So here is the jiggy;

I want to RESTORE the MODIFIED program TO ITS PREVIOUS STATE BEFORE IT WAS ''BUGGED'',, yeah I know which program needs to be ''restored'', but have no idea how to restore it to its state with all my own text in it.

Any advice? I am extremly depressed....

PS! As u can tell, the particular program (containing my headers and texts) is NOT deleted, but changed suddenly when using it, causing me to loose all my stuff on it. I dont need to restore a deleted file, I need to restore a modified file to its previous condition.

´Thank you.